The present invention relates to a differential structure for a remotely controlled toy car, which employs less gears to lower the cost and achieves a good differential effect with sufficient torque.
FIGS. 5 and 6 show a conventional differential used in a remotely controlled toy car. Four conic gears 91 meshing with each other are installed in a housing to provide differential adjustment for left and right shafts 81, 82 during turning. The conic gears 91 are engaged with each other in a line-to-plane relationship. In the case of high rotary speed, the conic gears 91 are quite subject to abrasion. Therefore, the parts are frequently replaced. FIG. 7 shows an improved differential in which spiral gears 92 are disposed between the left and right shafts 81, 82. The adjacent spiral gears 92 are engaged with bevel gears 93 on upper and lower sides. When rotated, the engaged spiral gears 92 and the bevel gears 93 transmit the power, whereby an apparent differential effect is achieved between the left and right shafts 81, 82. Therefore, during turning, the wheel on one side runs faster, while the wheel on the other side runs slower so as to avoid slipping. In such structure, the number of the gears is up to 14 so that the manufacturing and assembling procedure is complicated and the cost is increased. Moreover, the bevel gears are paralley engaged with each other. This fails to provide maximum torque.